<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>外边距</title>
    <style>
        div {
            width: 200px;
            height: 200px;
            background-color: pink;
            /*border: 1px solid transparent;*/
            /*box-sizing: border-box;*/
        }
        .one {
            margin-bottom: 200px;
        }
        .two {
            margin: 300px;
        }
        .three {
            margin: 0 auto;
        }
        .father {
            margin-top: 100px;
            padding-top: 0.1px;
        }
        .son {
            margin-top: 150px;
            width: 100px;
            height: 100px;
            background-color: #ff6700;
        }
    </style>
</head>
<body>
<!--<div class="one">1</div>-->
<!--<div class="two">2</div>-->
<!--<div class="three">3</div>-->
<div class="father">
    <div class="son">

    </div>
</div>
</body>
</html>